Don't declare move constructors for Iterator unless c++11

include/VersionedMap.h

@@ -101,8 +101,10 @@ struct __attribute__((__visibility__("default"))) VersionedMap {
     ~Iterator();
     Iterator(const Iterator &);
     Iterator &operator=(const Iterator &);
+#if __cplusplus > 199711L
     Iterator(Iterator &&) noexcept;
     Iterator &operator=(Iterator &&) noexcept;
+#endif
 
     struct VersionedMutation {
       /** param1 is guaranteed to have an addressable null byte at